Process of producing ammonium chlorid.



EMIL NAUMANN, OF COLOGNE, GERMANY.

PROCESS OF PRODUCIN G AMIMONIUM OHIiORID.

Specification of Letters Patent.

Patented June 30, 1908.

Application filed. .Tanuhry 17, 1908. Serial N 0. 411,208.

To all whom it may concern:

Beit known that I, EMIL NAUMANN, a subject of the German Emperor, and aresident of Cologn e, in the Kingdom of Prussia, Germany, have inventedcertain new and useful Imlprovements 1n. Processes of Producing Ch oridof Ammonium, of which the followmgrls'a specification.

his invention has reference to a novel process of producing chlorid ofammonium or sal ammoniac from sulfate of-ammonium and chlorid of sodiumin a hot aqueous solution.

It is the special object of this invention to produce a ure ammoniumchlorid.

The met ods heretofore known for producing ammonium chlorid or salammoniac of a high grade in hot aqueous solutions did attam thisintended result onl in an indirect manner because considerab equantities of sulfate formed during the process will crystallize outwith the chlorid of ammonium when hot solutions containing the ammoniumchlorid and sulfateof sodiumare allowed to cool off. This necessitates aseparation of the ammonium chlorid from the sulfate of sodium which is arather tedious operation and reduces considerably the percentage of pureammonium chlorid so that at present hardly any quantities of sal ammomacare (produced according to this method.

Accor mg to the known recipes molecular proportions of sulfate ofammonium and chlorid of sodium are allowed to react in a hot aqueoussolution and care is taken to have the final concentration equal to asaturation with ammonium chlorid, for the solution is finally evaporateduntil an iridescent fine film of ammonium chlorid a pears on thesurface. Solutions obtained in t 11s manner contain to 100 partsof waterthe components of about 90 parts of ammonium chlorid as well as thecomponents of about 35 parts or more sulfate of sodium. During thecooling off to ordinary tem erature of such a hot solution contalnm tiecomponents for both salts, the

ClllOIlt of ammonium crystallizes out and also about two-fifths of thesulfate of sodium presentwhich is an impurity to the chlorid ofammonium. h

Accordin to this invention the water oresent at t 1e end of the reactionis socalculated that a solution is obtained containing a considerablysmaller percentage of chlorid of ammonium than one saturated accordingto old methods at boiling temperature. Assuming that a solution as beenprepared of such concentration as required for the urpose of thisinvention and that the chlorid of sodium is in excess of the molecularproportion, the reaction between the quantity of sulfate of ammoniumemployed and a corre- .sponding molecular proportlon of chlorid ofsodium takes lace exactly as before when no excess of ch orid of sodiumwas present. From the excess of sodium chlorid additional uantitiesenter the reactive solution and isiplace therein part of the formedsulfate of so ium with the result of reducing the quantity of same. Thisreduction isin proportion to the ortion of the excess of sodium chloridwhicii enters the solution. By kee ing the concentration of the solutionwithin certain limits, the reduction of the formed sodium sulfate willbe such that the hot reactive solution upon cooling to normaltemperature will yield not only a. grade of crystallized chlorid ofammonium which contains considerably less of the sulfate of sodium thanformerly obtained according to known methods, but the water present willkeep-1n solution at normal-temperature all the sulfate of sodium whichremained in solution at the temperature at which the reaction tookplace, so that, upon coolin off such a solution an ammonium chloricrystallizes out which is free from sulfate.

The reactive solutions obtained according to the known methods all showthe same undesirable high percentage of sulfate of sodium, no matterwhether to a quantity of sulfate of ammonium employed a molecularproportion of chlorid of sodium is used or a great excess of same. Inthe resulting highly concentrated solution of the chlorid of ammoniumthe chlorid of sodium cannot exist in solution.

If reactive solutions obtained from molecular proportions, of sulfate ofammonium and chlorid of sodium shall lpossess the power of dissolvingeven; a smal er uantity of the excessive sodium chlorid, t e quantity ofwater for which the batch must be calculated so that finally asolution'is obtained containing a considerably smaller percentage ofchlorid of ammonium than corresponds to a quantityof arts of chlorid ofammonium in 100 parts 0 water. The reactive solu tions show then a powerof dissolving excessive chlorid of sodium whichincreases in proactivesolutions whose portion to the reduction of the concentra tion of theammonium chlorid.

In order to render it possible to obtain reower of dissolving excessivesodium chlorid permits of adding such a quantity of sodium chlorid aswill be suflicient to effect an economical reduction of the quantity ofthe undesirable sulfate, it

is necessary to work with solutions of less concentration thancorresponds to 75 parts of ammonium chlorid in 100 parts of water. If,however, the quantity of water is so calculated that a final solution isobtained contain- I ing about 60 parts of ammonium chlorid or less in100 parts of water and to such solution an excess of sodium chlorid isadded according to 15 parts in 100 parts of water of the final reactivesolution,- then the conditions are such that a sufficient ciuantity ofexcessive chlorid of sodium is ta en up by the hot reactive solution.,By this the quantity of sulfate of sodium has been so greatly reducedthat the water now present will hold in solution all the sulfate even ifthe temperature has been lowered to 17 C. and during the coolingammonium chlorid crystallizes out.

eva orated while the reaction takes place.

xample: A solution of about 60 parts of ammonium sulfate in 100 parts ofwater corresponding to a probable concentration of about 50 parts ofammonium chlorid in 100 parts of water is heated to a temperature of.

C. or more and an excess of sodium chlorid in solid form added whilestirring. The excess of sodium chlorid is advantageously calculated tobe about 15 parts to 100 parts of the water present. After the reactionhas taken .place between the ammo nium sulfate and a molecular roportionof sodium chlorid there is still a sufficient excess of sodium chloridwhich dissolves in effective guantities in a short time. The reaction isnished in about one to two hours according to the grade of fineness ofthe sodium chlorid employed and the intensity of stirring.

The quantity of sodium sulfate has been reduced in the reactive solutionby thedissolution therein of part of the excessive sodium chlorid tosuch an extent, that only chlorid of ammonium crystallizes after thesolution has been se arated from the solid parts of the charge an cooledto normal temperature. The ammonium chlorid thus obtained is freed fromadhering mother lye by known methods. In order to make the processcontinuous, the mother lyes remaining from the cold reactive solutionsare'reinforced byadding ammonium sulfate so that the necessary quantityof ammonium is present. The reinforced solutions are treated with anexcess of sodium chlorid like the original solutions whereby thedescribed solutions are obtained from which during coolingto normaltemperature only ammonium chlorid crystallizes.

Having thus described my invention I claim as new and desire'to secureby Letters Patent:

1. The-process of producing-chlorid of ammonium or sal ammoniac fromsulfate of ammonium andchlorid of sodium in hot aqueous solutionconsisting in producin a solu tion containing both salts of which hech10 rid of sodium is in excess of the molecular proportion necessaryfor the decomposition of the sulfate of ammonium and select' suchconcentration that the finally obtaine hot reactive solution containsless of the comr Y of same.

monium or sal ammoniac from sulfate of ammonium and chlorid of sodiumin"hot-.aqueous solutlon consisting l-Il producing a solution containingboth salts of which the chlorid of sodium is in excess of the. molecularproportion necessary for the decomposition of the sulfate of ammonium;-and selectin such concentrationthat the finally obtained hot reactivesolution contains less than 75 parts of the components of chlorid ofammonium to 100 parts-of water and cooling said solution tonormaltemperature whereby chlorid of ammonium. alone -crystallizes.

3. The process of producing chlorid of ammonium or sal ammoniac fromsulfate of ammonium and chloridof sodiumin hot aqueous solutionconsisting in producing a solution containing about 60 parts of sulfateof ammonium to 100 parts of water corresponding to about the componentsof 50 parts of chlorid of ammonium to 100 parts of water, heating saidsolution to a temperature of 70 C. or more, adding an excess of chloridof sodium insolid form while stirring, transforming completely thesulfate of ammonium into the chlorid of ammonium, and cooling thethusobtained hot reactive solution which also contains free dissolvedchlorid of sodium whereby only chlorid of ammonium crystallizes.

4. The process of producing chlorid of ammonium or sal ammoniac fromsulfate of amture of 70 Cher more, adding an excess ponents of chloridof ammonium than corresponds to a hot saturated reactive solution] f 2.The process of producing chlorid of amchlorid of sodium in solid formwhile stirring, temperature whereby only chlorid of amto such an extentas necessary to obtain a remonium crystallizes.

. 10 active solution completely saturated with Signed at Cologne,Germany, this 3d day chlorid of sodium, transformin completely ofJanuary 1908. 5 the sulfate of ammonium into tie chlorid of EMIL NAUMANN.

ammonium and cooling the thus obtained Witnesses: hot reactive solutionwhich also contains Louis VANDORY, free dissolved chlorid of sodium tonormal BESSIE F. DUNLAP.

